One of these was a trial by Ahmed Elgazzar from Benha University in Egypt. In this trial of patients with severe Covid-19, one group received ivermectin while the other, the control group, received hydroxychloroquine (people in this group should have received a placebo). According to the researchers, there was a 90% reduction in deaths in the ivermectin group, a degree of effectiveness strikingly at odds with most other studies of ivermectin and considerably better than even FDA-approved therapies for Covid-19.

A British medical student, Jack Lawrence, was assigned to evaluate the Elgazzar paper for a course and encountered a potpourri of apparent plagiarism and data fabrication. The Elgazzar paper had not been formally published in a medical journal, but had appeared instead on a preprint website called Research Square. Upon learning of Lawrence’s analysis, Research Square promptly retracted the paper.

Gideon Meyerowitz-Katz, an Australian chronic disease epidemiologist who also reviewed the Elgazzar data, found faults similar to Lawrence. Researchers often summarize large bodies of literature by statistically synthesizing trials in what are called meta-analyses. “If you remove this one study from the scientific literature,” he told The Guardian “most meta-analyses that have found positive results would have their conclusions entirely reversed.”